HO PLEISTOCENE OF INDIANA AND MICHIGAN. 



channel well toward its north end, which, during brief halts like those at Fall Creek and White 

 River, was utilized and in places expanded by streams issuing from the margin. In this manner, 

 perhaps, may be explained the greater size of the part of the channel between White River and 

 Fall Creek as compared with that south of Fall Creek. 



Material in the channel. — Borings have been made in or near the borders of the channel 

 at Fairmount, Summitville, Alexandria, Anderson, Huntsville, and Greenfield. Rock rises 

 nearly to the surface at Fairmount near the line of Grant and Madison counties, being struck 

 at 5 to 30 feet. At Summitville a boring for gas a few rods east from the channel passed through 

 15 feet of till and a great depth of gravel, evidently older than the channel, and struck rock 

 at 111 feet. At Alexandria the rock is struck at slight depth in the valley of Pipe Creek and 

 on the uplands, so there is probably but little drift beneath the abandoned channel in the vicinity 

 of this town. At Huntsville a gas boring near the east side of the channel penetrates 20 feet 

 of drift, mainly muck and boggy material. 



The esker. — The esker in this channel extends from the White River bluffs in the north 

 part of Anderson nearly south-southeast for about 4| mdes to the north line of Fall Creek 

 Township in sec. 2, T. 18 N., R. 7 E. It has a height of 10 to 40 feet and a breadth of 50 to 150 

 yards and is nearly continuous, being broken only by small gaps and by a few places where it 

 is very faint. In the southwest part of Anderson, near the corners of sees. 13, 14, 23, and 24, 

 it is most prominent. It is narrow to within one-half mile of its north end, where it expands 

 into a level-topped ridge 100 to 200 yards wide, on which the courthouse and main business 

 portion of the city is built. It stands 30 feet or more above the channel, which here lies almost 

 wholly on the west. It is separated on the east from the uplands by a slight sag 8 to 10 feet or 

 less below the level-topped portion and but 50 to 75 yards in width. The esker at its north 

 end has very nearly the same altitude as the uplands east of the sag, 880 feet above sea level; 

 near its southern end it rises in places 20 feet or more above the bordering uplands, the channel 

 in which it lies being depressed about 15 feet below the upland plain. 



So far as opened this esker is composed mainly of fine gravel or gravelly sand. Several 

 wells along it in Anderson have penetrated gravel to 40 or 50 feet; and one well, at the residence 

 of Charles Henderson, to 91 feet, a level slightly below that of White River. The lower part 

 of this gravel may, however, be older than the esker. This abandoned channel has much 

 gravel beneath it wherever borings have penetrated it, but as the gravel extends in places out- 

 side the limits of the channel it is likely to be in part older. 



The structure and thickness of the drift are exceedingly variable in the vicinity of Anderson. 

 On the esker at Charles Henderson's residence gravel was penetrated to 91 feet without reaching 

 rock. At the strawboard factory in the abandoned channel only 16 feet of drift was found. 

 At the glass works southwest of Anderson in the abandoned channel a boring passed through 

 194 feet of drift, all sand and gravel. In Killbuck Creek valley north of White River a gas boring 

 encountered 50 feet of gravel and sand. On the north bluff of White River near the crossing 

 of the Pittsburgh, Cincinnati, Chicago & St. Louis and Cleveland, Cincinnati, Chicago & St. 

 Louis radways a gas well passed through 191 feet of drift, of which a large part was till. A 

 water well west of the crossing of the same railways in Anderson penetrated much till and did 

 not reach the bottom of the drift at a depth of 104 feet. On the uplands west of the abandoned 

 channel about 2J miles southwest from the courthouse a water well penetrated 160 feet of 

 drift, mainly till with thin beds of fine sand, without striking rock. These records indicate that 

 the altitude of the rock surface beneath the abandoned channel changes fully 160 feet within a 

 short distance. 



A fine gravel constituting the bulk of the esker is exposed in a pit near its south end. The 

 bedding is discordant in the lower part but is nearly horizontal in the upper. A capping of 

 brown clayey gravel ranges from a few inches to several feet in thickness. The cobblestones, 

 which are numerous in the fine gravel, and the smaller pebbles are nearly all of limestone and 

 are apparently of the same kind of rock as the underlying strata, Silurian limestone. A col- 

 lection of pebbles an inch or less in diameter, gathered without attempt at selection, were 

 classified as follows: 



